The semiconductor integrated circuit (IC) industry has experienced exponential growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component or line that can be created using a fabrication process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs. Such scaling down has also increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. In one example associated with lithography patterning, a photo mask to be used in a lithography process has a circuit pattern defined thereon and is to be transferred to wafers. A reflective mask is used during extreme ultraviolet (EUV) lithography process. However, the existing reflective mask is vulnerable to manufacturing fabrication, such as cleaning process, and is easily damaged.
Therefore, what are needed are the reflective mask and the method making the same to address the above issues.